1. Field of the Invention
The present invention relates to a system and method for automatically adjusting the position of a headrest of a vehicle seat assembly.
2. Background Art
Components of vehicle seat assemblies, including the seat cushion, seat back and headrest, are adjustable to a variety of user-defined seating positions to support a passenger in a vehicle. However, the adjustability of vehicle seat components, especially the headrest, are limited to systems that are adjusted by the vehicle occupant. The headrest assembly of the vehicle seat assembly extends upward from a top portion of the seat back of the vehicle seat adjacent the passenger's head to reduce the potential whiplash effect resulting from a rear impact collision.
Whiplash injuries are one of the most common injuries suffered by passengers in a vehicle. Whiplash is a general term for a set of common symptoms involving the soft tissues of the head, neck and spine, associated with the rapid motion of the head and neck. Typically, such whiplash injuries occur in rear impact vehicle collisions, wherein the forces generated by the vehicle collision accelerate the unsupported head and neck away from the restrained torso, causing significant body damage. The headrest is provided on the vehicle seat to restrict rearward travel of a passenger's head relative to the passenger's body during a collision.
One significant limitation of common headrest assemblies is that the headrests are manually positionable on the seat by the vehicle passenger, which may or may not protect passengers of different sizes who occupy the seat. For example, the headrest may not protect the head and neck of a tall passenger in a collision if a previous short passenger set the headrest at a lower height. A manually adjustable vehicle headrest may also obstruct the sight line of the driver through the rear window of a vehicle if not repositioned after use, creating a dangerous blind spot for the driver.
It would be advantageous to provide a vehicle seat assembly having a control system for automatically adjusting the position of the headrest based on the occupancy of a vehicle seat. It is also desirable to provide a vehicle seat assembly having an automatic headrest adjustment control system that positions the headrest adjacent a passenger's head in the event of a rear impact collision. It is further desirable to provide an automatic headrest adjustment control system that removes the headrest from view based on feedback from occupant detection sensors when a seat is unoccupied in the vehicle.